Art of controlling electrical switches operated by electromagnets.



5 54. PATENTED JULY 19 1904. N0 76 w. GRUNOW, JR.

ART OF CONTROLLING ELECTRICAL SWITCHES OPERATED BY ELEGTR'OMAGNBTS. Arrpmmlon FILED we. 2, 1902.

no 110 EL.

(7 a n MOTOR TO FEEDER UNITED STATES Patented July 19, 1904,

PATENT OFFICE.

ART OF CONTROLLING ELECTRICAL SWITCHES OPERATED BY ELECTROMAGNETS.

SPECIFICATION forming part of Letters Patent No. 765,654, dated July 19, 1904.

Application filed August 2, 1902.

To all whom it may concern:

Be it known that 1, WILLIAM GRUNow, J r.,

a citizen of the United States, residing at.

Bridgeport, in the county of Fairfield and State of Connecticut, have made a new and useful Invention in the Art of Controlling Electrical Switches Operated by Electromagnets, of which the following is a specification.

My invention is directed particularly to im provements in the art of controlling electrical switches for effecting the manipulation of curand in such manner that the working current is not interfered with in its functions or permitted in any way to damage the apparatus.

Referring now to the drawings for a full and clear understanding of the invention, such as will enable others skilled in the art to construct the apparatus hereinafter described and to practice the method claimed, Figure 1 is a side elevational view of a novel form of switch designed to practice the method hereinafter claimed, the working current terminals, the operating-solenoids, and certain of the interconnected parts being shown in sectional view and the circuits in diagrammatic view. Fig. 2 is a sectional view taken through Fig. l on the broken line X X and as seen looking thereat from the top toward the bottom of the drawings. Fig. 3 is a detail side elevational view of the upper portion of the switch illustrated in Fig. 2.

W i t h electromagnetically c 0 n t r o l l e d switches for sectional systems of electric railways such as have heretofore been devised much annoyance has resulted from damaging arcing at the working contacts or terminals and from what is known in the art as chattering between said contacts or terminals,

Serial No. 118.239- (No model.)

owing to the fact that as a rule such switches are operated by electromagnets or solenoids of the double-coil typethat is to say, a primary or high-resistance coil is utilized to cause a solenoid-core carrying the movable terminal to primarily effect the closure of the circuit after which the terminals are held in permanent contact with each other by the working current flowing directly through a low-resistance coil which acts upon the same solenoidcore, the ampere-turns of the coil being in series relation with the working current to the motor or other translating device designed to utilize such current. My invention is designed to overcome this objectionable feature, and to this end I provide a solenoid or electromagnet whichprimarily acts upon a solenoid-core operatively connected with the movable terminal in such manner that the working circuit is first closed by the action of this solenoid, and when thus closed a multiple are or branch circuit from the working circuit is closed through a low-resistance solenoid acting upon a balanced lever connected with the movable terminal, which lever is proportionately so fulcrumed as to effectually hold the terminals in working contact with each other, after which the first-named circuit is broken by a releasing device, a definite time interval occurring between the time that the working circuit is first closed and the circuit-closing circuit is interrupted, thus causing the operation of the apparatus to be effected through a series of successive steps, which avoid or prevent both areing and chattering.

Referring now to the drawings in detail, in all of which like letters and numerals of reference represent like parts whenever used, 8 is a sectional third rail and f a branch feeder running to a metallic terminal 3 in the switchbox.

0 is a current-collector or trolley-shoe carried by a moving car, one of the wheels of which (not shown) rests upon a tram-rail t, constituting the return conductor to the power-house generator, (not shown,) but having its positive pole connected to the feedercircuit.

5 5 represent the carbon terminals, both of which are secured in conducting-cups 6, the

upper one being the fixed terminal electrically connected with a metallic terminal 2 by an angle-iron 8 and conductor 7 of relatively low resistance.

1 is an insulating base-board, to which the two metallic terminals 2 and 3 and all of the operative parts of the switch are secured.

4: is a flexible conductor connected to the metallic terminal 3 and to the lower surface of the metallic cup 6, which holds or secures the lower movable carbon terminal 5, said cup and carbon terminal being supported by an insulating sleeve or pin 15, to the lower end of Which is secured a solenoid-core 16, all of said parts being held together by a rod 29 and pivotally supported by a proportional lever 9, fulcrumed, as shown, above an iron-clad operating-solenoid 17, 18 being the iron-clad structure. The short end of the proportional lever is pivotally connected to the insulating sleeve or pin 15 by a metallic band, which surrounds the same, the arrangement being such that vertical adjustment may be efiected for the lower carbon terminal through the agency of the rod 29, which connects the two parts of the insulating sleeve or pin 15. To the free end of the proportional lever 9 is secured a solenoid-core 10, adapted to move vertically into the magnetic field of a second iron-clad solenoid 11 and core 13, 12 representing the iron-clad portion thereof.

14 is a branch or shunt circuit of relatively large current-carrying capacity operatively connected to the coils of the solenoid 11, which coils, it will be understood, are of relatively low resistance and bear a definite or fixed proportion to the low-resistance conductor 7. In other words, the low-resistance coil 11 is in shunt-circuit to the conductor 7 and adapted to utilize a part of the working current for holding the carbon terminals 5 5 in working relation with each other.

19 is a conductor running from the metallic terminal 3 to therelatively high-resistance coils of the solenoids 17 and thence to the pivoted end of a lever c, fulcrumed at one end upon a standard 8, secured to the ironclad casing 12 of the solenoid 11, the free end of said lever resting upon a pin 3), carried by the long arm of the proportional lever 9. (See Fig. 2.) This lever 0 is made, preferably, of insulating material and carries upon its upper surface two good conducting-rails r 1, preferably of copper, the ends of which are connected directly in circuit with the conductor 19 and to a resistance-bar 22, preferably of carbon.

6 is a metal ball of good conductivity, such as copper, adapted to have good surface contact with the inner faces of the rails 0 and thus complete the circuit through the conductor 19. The free ends of the rails rrterminate a short distance from the free end of a turned-up or hook-like portion, as shown,

.which acts as a stop for the ball I) when the free end of the lever is in its lower position, as shown in dotted lines, Fig. 1, the arrangement being such that when the ball is in this position it is entirely out of metallic contact with the rails o" 9". Under normal conditions when the sectional third rail or conductor 8 is disconnected from the feeder the operative parts of the switch are located, as disclosed in Fig. 1, with the carbon electrodes 5 5 separated, the free end of the lever c in its upper position, and the conducting-ball I) resting upon the rails r 1 near the pivoted end of the lever. 1

The operation is as follows: As the currentcollector or trolley-shoe 0 passes from the sectional third rail 8, upon which it is resting, the front end thereof makes metallic contact with the next sectional third rail in advance, thereby closing the current from the sectional conductor 8 in advance by the corresponding branch conductor f terminal 3, conductor 19, coils of the solenoid 17, conductor 19, metal rails r r, carried by the lever 0', ball 6, resistance 22, conductor 23 to the tram-rail t and thence back to the starting-point, the negative pole of the power-house generator. (Not shown.) This causes the solenoid-core 16 to be lifted until the carbon contacts 5 close the working circuit. Consequently the free end of the proportional lever 9 is moved downward, with the solenoid-core 10 passing into the solenoid 11. The pin 1), carried by the long arm of the proportional lever, is correspondingly depressed, and consequently the several parts assume the positions shown in fine dotted lines in Fig. 1. The ballb therefore commences to roll down the inclined plane,

and after a predetermined length of time, dependent upon the inclination of this plane, the circuit is interrupted at the outer or righthand ends of the rails r 1, (see Fig. 2,) the ball ultimately resting in the position shown in dotted lines in that figure against a hooked stop at the free end of the'insulated lever. Hence the working circuit is closed, and the current now flows through the low-resistance coils of the solenoid 11, maintaining the circuit closed and without chattering or damaging arcing. With such a device the time interval may be increased or diminished, as desired, by changing the inclination of the lever c, which may be effected by adjusting the pin p at different points upon the long arm of the proportional lever 9 or by raising or lowering the pivoted end of the lever in a manner which will be obvious to those skilled in the art.

By the expression proportional or proportioned lever (indicated by the numeral 9 in the drawings and referred to in the specification) I wish to be understood as meaning a lever having a long and a short arm so proportioned that a delicacy of operation is effected whereby the terminals are held together by the action of the solenoid 11 upon its core 10 with the greatest nicety, such an arrangement making it possible to secure a certainty of action whereby the terminals are always maintained in contact with each other when working current is flowing through the branch feeder f running to its corresponding sectional conductor or third rail 8.

In the practice of my method hereinafter claimed I do not limit myself to the use'of the specific type of apparatus disclosed in the accompanying drawings and described in the foregoing specification. I believe it is broadly new with me to prevent arcing or chattering at the terminals of an electric switch by first closing the same through a switch-controlling circuit and then breaking the controlling-circuit a predetermined length of time after the working circuit is closed to the translating devices by the application of a retarded force, and my claim is generic as to this method of operation.

Although I have described my invention hereinbefore as applicable to a sectional thirdrail system of electric railways, obviously the same may be used in connection with systems of electrical energy generally and with various types of electrical translating devices wherein currents of high potential and large quantity are utilizedsuch, for instance, as electric motors, electric lamps, and kindred apparatusand my claim hereinafter made is designed to be of such scope as to include the practice of the method described when applied to all such types of apparatus.

I make no claim hereinafter to the apparatus hereinbefore disclosed and in the use of which the methods hereinafter claimed are practiced, as this feature constitutes the subject-matter of a divisional application filed by me in the United States Patent Oflice on the 17th day of May, 1904;, bearing Serial No. 208,47 7

Having thus described my invention, what I claim, and desire to secure by Letters Patcut, is

The described method of eflecting circuit connection between a source of electrical energy and a translating device without damaging arcing, consisting in utilizing a part of the current to primarily close the working circuit; then utilizing the working current to maintain the working circuit firmly closed and finally interrupting the flow of the first-named current after a definite time interval by the application of a retarded force.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM GRUN OW, JR.

Witnesses:

C. J. KINTNER, M. F. KEATING. 

